The existence of horizontal envelopes in the 3D-Heisenberg group
arXiv:1801.04447
Abstract
By using the support function on the -plane, we show the necessary and sufficient conditions for the existence of envelopes of horizontal lines in the 3D-Heisenberg group. A method to construct horizontal envelopes from the given ones is also derived, and we classify the solutions satisfying the construction.
10 pages, 2 figures